It is quite common to see both diabetes and thyroid problems in the general population but is there an association between the two? While experts say some studies suggest a link, it is a very complex relationship. They say the association between thyroid disease and type 1 diabetes is that they are both autoimmune disorders. And in type 2 diabetes, thyroid disease may rarely cause hypoglycemia (low sugar).
What is the thyroid gland?
The thyroid is a butterfly-shaped gland present in the neck. It releases the hormones – T4 (thyroxine) and T3 (triiodothyronine) when it is triggered by the thyroid-stimulating hormone (TSH), which is released by the pituitary gland. Dr David Chandy, consultant endocrinologist, Sir H NReliance Foundation Hospital and Research Centre, Mumbai, says, “It regulates the entire body’s metabolism, from head to toenail. If the thyroid is weak [hypothyroidism], all the body’s processes will slow down and if it is high [hyperthyroidism], everything in the body will work faster.” Hence, for every function of the body, one needs the correct amount of thyroid.
Symptoms of hypothyroidism
- Hair loss
- Constipation as digestion slows down
- Weight gain
- Dry skin
- Puffy face
- Heart rate may slow down. So, the BP may go up slightly
Symptoms of hyperthyroidism
- Faster heartbeat, causing palpitations
- Frequent passing of stools (about four to five times a day) as intestines work faster
- Tremors in hands as muscles contract faster
- Sweaty skin
- Bulging eyes
- Weight loss
Autoimmune disorders can often cause both hypothyroidism and hyperthyroidism. Hypothyroidism is more common than hyperthyroidism, among women and people with obesity. Dr A Sharda, consultant, endocrinology and diabetology, Manipal Hospital, Millers Road, Bengaluru, adds, “Hyperthyroidism, where T3 and T4 levels are high, is usually caused by autoimmune disorders, Graves’ disease or thyroiditis, causing inflammation of the thyroid gland. On the other hand, hypothyroidism, where T3 and T4 are low, is commonly due to an autoimmune condition called Hashimoto thyroiditis.”
Are thyroid problems and diabetes related?
Experts say the link between type 1 diabetes and thyroid problems is that both are autoimmune disorders. Dr Chandy says, “In type 1 diabetes, the immune system is overactive and troubles the pancreas. The pancreas get weak and will not make insulin. Now, both hypothyroidism and hyperthyroidism are usually auto-immune disorders and so, people with type 1 diabetes have more chances of developing thyroid problems. 15 to 30 per cent of children with type 1 diabetes will have thyroid issues.”
Experts say there is no direct relationship between type 2 diabetes and thyroid issues. As both conditions are common, they are likely to be present together, they say. Dr Sharda, adds, however, there is also some meta-analysis that shows that there is a bi-directional relationship between the two. “It shows up to 9.4 per cent of people with type 2 diabetes can have hypothyroidism. Variation in thyroid levels even within normal range can trigger the onset of type 2 diabetes, particularly in people with prediabetes,” she says.
Can thyroid problems cause type 2 diabetes?
Dr Sharda says some studies suggest a J-shaped curve relationship between the two. “The higher the TSH levels, the more the chances of type 2 diabetes and as TSH levels start coming down, the prevalence of type 2 diabetes reduces. Another complex relationship between thyroid disease and diabetes is that if a type 2 diabetic develops hypothyroidism, there can be chances of developing hypoglycemia (low sugar),” she says.
Dr Chandy adds, “If one has severe hypothyroidism, then it can affect the stomach and the person will be unable to digest the food completely. In that very small category of people, rarely, the sugar can go low.” Hence, Dr Sharda recommends that if a type 2 diabetic is on regular medication and yet, develops low sugar, it is good to get the thyroid hormones checked. “If anybody is a type 1 diabetic, they should definitely check the thyroid levels every year,” she adds.
Experts point out that since both conditions are different, they are treated separately. They say it is easy to manage and treat thyroid issues with regular medications. Dr Chandy says, “The doctor will ask to get a blood test done regularly to check the TSH levels and adjust the dosage of the medicine accordingly. One need not worry much about the sleep or exercise routine for hypothyroidism. Hyperthyroidism can also be managed with medication but they may cause side effects, like low sugar and reduction of white blood cells, very rarely.” For diabetes, he says, one needs to ensure a proper diet, which is low in carbs and do regular exercise.
Takeaways
- The thyroid is a butterfly-shaped gland present in the neck, which produces T3 and T4 hormones.
- Thyroid gland regulates the entire body’s metabolism.
- Hypothyroidism or low levels of thyroid hormones is more common among women and people with obesity.
- As thyroid issues and diabetes are common conditions, experts say they are more likely to be present together.
- The link between thyroid issues and type 1 diabetes is that both are autoimmune disorders.
- In people with type 2 diabetes, thyroid issues may rarely affect sugar levels, causing hypoglycemia.
- Both conditions are treated separately. While thyroid issues can be easily managed with medicines, diabetes management requires lifestyle modifications, including proper diet and regular exercise for at least 30 minutes for five days a week.
